O-ring cord is a rubber cord with a circular profile that can be cut to the required length. O-ring cord can be used as a static seal for when standard sizes are either unavailable or too costly. Types of O-Ring Cord: O-ring material selection is based on chemical compatibility, application temperature, sealing pressure, lubrication requirements and durometer with many options available in the following materials:• Nitrile O-rings (NBR)• Viton® O-rings (FKM)• Silicone O-rings• Neoprene® O-rings• EPDM O-rings• Viton O-ringsWhere are they used? O-rings are commonly used for their sealing properties, and are often used to keep air and liquids from passing in or out of any given area.